Controlling method and apparatus for integral personal computer and CD-player

ABSTRACT

A CD replay device, which includes an ejection button for controlling the ejection of a CD and which reads data on a surface of the CD. A disk ejection operation is performed when the ejection button has been depressed for a period of time that is less than a predetermined period. The replaying of a CD begins when the ejection button has been depressed for the predetermined period of time or longer.

FIELD OF THE INVENTION

The present invention relates to a CD replay device that reads data thatare recorded on the surface of a compact disk (CD), and a method forcontrolling such a device. More particularly, the present inventionrelates to a CD replay device that can be connected to a portableinformation processing apparatus, such as a notebook computer, and to amethod for controlling such a device. The present invention also relatesto a CD replay device that is incorporated in a notebook computer andthat can easily play a music CD without interrupting an application thatis being executed by a computer and to a method for controlling such aCD replay device.

BACKGROUND OF THE INVENTION

Compact, light personal computers (also called "portable computers" or"notebook computers") built from designs that take portabilityconsiderations into account are in wide use today. Also, as compactauxiliary storage devices have been produced, certain notebook computersare now available that can incorporate a CD-ROM drive (CD replay device)in addition to a hard disk drive (HDD) and a floppy disk drive (FDD). Asan example, the ThinkPad 755CD (an IBM Corp. trademark), a notebookcomputer that is sold by IBM Japan Ltd. incorporates a CD-ROM drive.

FIG. 1 shows an outline illustration of a notebook computer 1. Thenotebook computer 1 in FIG. 1 is so designed that a lid 5, which has aninternally mounted liquid crystal display panel (LCD) 4, is rotatablyhinged with a main body 3, almost at the rear edge of the main body 3.In the main body 3, which has a keyboard 2, are a CPU, a main memory, aROM, peripheral controllers, and a system board on which is a bus bywhich these components (none of them shown) are connected. A batterypack (not show:n), an HDD (not shown), and a CD-ROM drive 50 areincorporated in the lower space of the main body 3 beneath the keyboard2. A disk tray for the CD-ROM drive 50 is slideably mounted under themain body 3 to facilitate the exchange of disks. On the front face ofthe disk tray 51, an ejection (Eject) button 6 is provided to controlthe ejection of the tray. At its rear, the CD-ROM drive 50 is attachablyconnected to the bus on the system board (not shown) and can be removedand replaced by another peripheral device, such as an FDD.

The recording on a CD, i.e., a compact disk (hereafter also referred tosimply as a "disk"), is performed by forming pits (which have raised anddepressed shapes that differ in reflectivity) that correspond to digitaldata on one face of a disk, which is formed of a transparent resin, andby overlaying an extremely thin metal film of, for example, aluminum anda further hard protective film. The CD-ROM drive (CD replay device)focuses a laser beam on a rotating disk, and employs the changes in theintensity of reflected light to read data. Since a great amount of datacan be recorded on a CD at high density, a CD is employed for therecording not only of computer data but also of audio data, image dataand various other data.

The physical and logical specifications for a CD were determined by agroup of which Sony Corporation and Philips Ltd. were the centralfigures, and are described in a "Reads Book," a "Yellow Book,". and a"Green Book," to use the common titles.

A CD is so designed that data are recorded spirally from the center ofthe disk surface to the outside and in the same density. The physicalformat is classified roughly into three areas: from the center of thedisk face, a lead-in area, a program area, and a lead-out area. Thelead-in and the lead-out areas are employed for recording attributeinformation for a disk and various control information concerning, forexample, start positions for the individual tracks.

The program area is employed for recording the substantial user data,such as computer data and audio data, and is constituted by a single ora plurality of tracks. A track can be divided into frames that are 24bytes long. The length of a track is not constant and varies dependingon the length of the user data that are recorded. In case of a music CD,for example, one track corresponds to one piece of music, and the tracklength corresponds to the playing period.

A track on which computer data are recorded is called a "CD-ROM track,"and a track on which audio track are recorded is called a "CD-DA track".In addition, as one type of a CD-DA, there is a "CD-Graphics" whereimage data are recorded in an empty area within the audio data (morespecifically a sub channel in a frame). As another type, there is ahybrid CD having mixed CD-ROM tracks and CD-DA tracks. Also, as otherstandards, there are "CD-I (Compact Disk-Interactive media), where imagedata and audio data are recorded on a single track with an interleavefactor (time- sharing multiplexing of a plurality of channels), and a"CD-ROM XA."

CD-DA specifications are given in a "Red Book," CD-ROM specificationsare given in a "Yellow Book," and CD-I specifications are given in a"Green Book." The CD-I specifications prescribe the standards forenabling dialogue operation, and the CD-ROM XA specifications prescribethe standards for the combining of audio data with animated data and fortheir joint handling as multimedia.

Generally, in the same way as with other peripheral devices, a CD-ROMdrive that is incorporated in a computer receives, through a bus, acommand that is issued in software, such as an application program or anoperating system (OS), so that it is controlled by a computer system(hereafter referred to simply as a "system"). The CD-ROM that replays amusic CD is no exception. The starting and stopping of a read, and thehead seek and set process for the next recorded musical piece will bediscussed in detail.

To perform the reading of a music CD by an incorporated CDROM drive, itis assumed that at least three kinds of programs should be loaded into amain memory of the system: an application program for the music CDoperation (hereafter referred, to as a "CD-PLAYER.EXE"), a file managerdriver that permits an OS to manage a CD-ROM as an external storagedevice (MSCDEX. EXE, etc. ), and a device driver for a CD-ROM drive"CD-PLAYER.EXE" must be executed when a read operation is to beperformed with a music CD. Since multitasking is not available with DOSenvironment, for example, the following procedures are required to run amusic CD during the execution of another application (DOS wordprocessing).

1. DOS word processing is temporarily terminated. (If a document isbeing prepared, it must be saved and the job is terminated.)

2. A mouse program is activated if it has not yet been loaded.

3. CD-PLAYER.EXE is executed.

4. A pertinent selection (replay, halt, etc.) from a Graphical UserInterface (GUI) screen menu is made by pointing and clicking with amouse and the results of the operation are relayed to CD-PLAYER.EXE.

5. CD-PLAYER.EXE is terminated.

6. DOS word processing is resumed.

Similarly, the following procedures are required to run a music CDduring the execution of another application (Windows application) onWindows.

1. The display for the Windows application that is being executed isminimized by a mouse operation, or a task is switched by depressing atoggle switch on a keyboard to provide a program manager window. 2. Theicon of a program group wherein a CD-PLAYER icon is registered isopened.

3. The CD-PLAYER icon is double-clicked to activate CD-PLAYER.EXE and adesired menu selection is clicked in the CD-PLAYER window. By referringto the above explanation, it would be understood by one having ordinaryskill in the art that, conventionally, playing a music CD on a computerpresents the following difficulties.

(1) Interruption of an application that is being executed.

To control the starting or halting of replaying, a dedicatedapplication, i.e., "CD PLAYER.EXE," must be activated every time. A busis normally used to input data at a keyboard or with a mouse, and totransmit a command to a CD-ROM drive. Since an interrupt occurs at aCPU, an application that is being executed is inevitably suspended.

(2) Use of system resources.

For frequent playing of music CDs, an application for operating a musicCD (e.g., CD-PLAYER.EXE) and specific drivers, such as a file managerdriver (e.g., MSCDEX.EXE) and a device driver, have to be resident inmain memory. Since a CD-PLAY2R. EXE program is generally from 70 to 200kilobytes, and since each of the drivers is about 35 kilobytes,together, these programs constitute a considerably large load on thesystem resources.

(3) Operability.

To play a music CD during the execution of another application, theapplication must be temporarily terminated and CD-PLAYER.EXE must beactivated (in the DOS environment), or windows must be switched and theCD-PLAYER icon must be selected and operated (in the Windowsenvironment). Also, the initiating operation is comparativelycomplicated. Since the user interface differs for each application, thisis another factor that contributes to the complication and thedifficulty of the operation.

In such an environment, even when a computer user becomes tired becauseof the work being done (e.g., the preparation of a document by wordprocessing) and decides to listen to music to relax, the operation toreplay a music CD requires the interruption of an application or theabove described input operations. This is troublesome for a user.

Further, there are some applications (e.g., CD-PLAYER-EXE) that do notpermit "working while listening to music"; and even if the replaying ofa music CD can be performed, it is terminated when such application isended. Even when an application can be terminated and the originalapplication (e.g., word processing) can be restarted while a music CD isbeing replayed, the application must be activated each time for asucceeding music CD operation (the head seek-and-set process for playingthe next recorded musical piece, or the playing ' halt), and furthermanipulation and time are required. It is clear that if several tens toseveral hundreds of kilobytes in a main memory are always used merelyfor audio data processing, not for computer data processing, systemresources are wasted. In other words, although a user has installed a CDreplay device in a computer system, such user cannot easily be refreshedby listening to music whenever desired.

On the other hand, since dedicated CD replay devices for playing musicCDs are equipped, as a standard, with special control buttons forindividual operations, such as replay start, replay halt, and the headseek-and-set process for the next musical piece, a user can replay musicCDs freely, any time desired. As for an incorporated CD-ROM drive,however, generally, only the front face of a disk discharge tray appearson the surface of the computer main body 1, as is shown in FIG. 1. Onsuch a limited surface, at most only an ejection button 6 is provided,and the addition of other control buttons increases manufacturing costs.Therefore, the operation of an incorporated CD-ROM drive relies on inputthat is performed at a keyboard or with a mouse. Accordingly, theoperation of the CD-ROM drive requires the use of the bus and theinterruption of an application program that is being executed.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an excellent CDreplay device that can be connected to a portable information processingapparatus, such as a notebook computer, and to a method for controllingsuch a CD replay device.

It is another object of the present invention to provide a CD replaydevice that is incorporated in a notebook computer and that can easilyrun a music CD without interrupting an application that is beingexecuted on a computer system, and to a method for controlling such a CDreplay device.

To achieve the above objects, according to a first aspect of the presentinvention, a CD replay device, which includes an ejection button that isused to control the ejection of a CD and which reads data on the surfaceof the CD, performs a disk ejection operation when the ejection buttonhas been depressed for a period of time that is less than apredetermined period, and begins to replay a CD when the ejection buttonhas been depressed for the predetermined period of time or longer.

According to a second aspect of the present invention, a CD replaydevice, which includes an ejection button that is used to control theejection of a CD and which reads data on the surface of the CD, haltsthe replaying of the CD when the ejection button has been depressed fora period of time that is less than a predetermined time during thereplaying of the CD, and begins to replay the next track on the CD whenthe ejection button is depressed for the predetermined time or longerduring the replaying of the CD.

According to a third aspect of the present invention, a method, forcontrolling a CD replay device that includes an ejection button that isused to control the ejection of a CD and that reads data on the surfaceof the CD, comprises the steps of: ejecting the CD when the ejectionbutton has been depressed for a period of time that is less than apredetermined period; and beginning the replaying of the CD when theejection button has been depressed for the predetermined period of timeor longer.

According to a fourth aspect of the present invention, a method, forcontrolling a CD display device that includes an ejection button that isused to control the ejection of a CD and that reads data on the surfaceof the CD, comprises the steps of: halting the replaying of the CD whenthe ejection button has been depressed for a period of time that is lessthan a predetermined time during the replaying of the CD; and beginningthe replaying of the next track on the CD when the ejection button isdepressed for the predetermined time or longer during the replaying ofthe CD.

According to a fifth aspect of the present invention, a method, forcontrolling a CD replay device that comprises a tray on which a CD isplaced, a command mechanism for inserting and ejecting the tray, anejection button to control the ejection of the tray, a read mechanismfor seeking data on the surface of the CD and for reading the data, adata processor for processing the data that are read, a line outterminal for relaying an analog output of the data that are read, aninterface for connecting the CD replay device to a bus of a computersystem, and a controller for controlling all the operations, comprisesthe steps of: forcing the operations of the command mechanism when theejection button is depressed for a period of time that is shorter than apredetermined time while the read mechanism is halted; beginning datareading by the read mechanism when the ejection button is depressed forthe predetermined time or longer while the read mechanism is halted; andoutputting the data that are read from the line out terminal.

According to a sixth aspect of the present invention, a method, forcontrolling a CD replay device that comprises a tray on which a CD isplaced, a command mechanism for inserting and ejecting the tray, anejection button to control the ejection of the tray, a read mechanismfor seeking data on the surface of the CD and for reading the data, adata processor for processing the data that are read, a line outterminal for relaying an analog output of the data that are read, aninterface for connecting the CD replay device to a bus of a computersystem, and a controller for controlling all the operations, comprisesthe steps of: halting data reading by the read mechanism when theejection button is depressed for a period of time that is shorter than apredetermined time during the data reading by the read mechanism; andskipping from a reading position on the CD to a succeeding track whenthe ejection button is depressed for the predetermined time or longerduring the data reading by the read mechanism.

According to a seventh aspect of the present: invention, a method, forcontrolling a CD replay device that comprises a tray on which a CD isplaced, a command mechanism for inserting and ejecting the tray, anejection button to control the ejection of the tray, a read mechanismfor seeking data on the surface of the CD and for reading the data, adata processor for processing the data that are read, a line outterminal for relaying an analog output of the data that are read, aninterface for connecting the CD replay device to a bus of a computersystem, and a controller for controlling all the operations, whereindata are read from a CD-DA track and an analog output of the data can betransmitted from the line out terminal, comprises: a timing step oftiming a period during which the ejection button is depressed; a firstdecision step of determining whether or not a CD-DA track is being readwhen, at the timing step, the period is a predetermined period orlonger; a second decision step of determining whether or not a CD hasbeen placed on the tray when, at the first decision step, no reading ofthe CD-DA track is being performed; a third decision step of determiningwhether or not a possibility exists that a CD-DA track is included onthe CD when, at the second decision step, the CD is determined to beplaced; a seeking step of seeking the next CD-DA track when, at thethird decision step, a possibility exists that the CD-DA track isincluded on the CD; and a playing step of reading data from the CD-DAtrack that is found at the seeking step and of providing at the line outterminal an analog output of the data that is read.

In the seventh aspect, when, at the playing step, the data reading fromthe CD-DA track has been completed, the following CD-DA track may besought on the CD and the replaying step may be repeated.

Further, in the seventh aspect, so long as the result obtained by eitherone of the second and the third decision steps is negative, the tray maybe ejected by the command mechanism.

In addition, in the seventh aspect, when, at the first decision step,data are being read from the CD-DA track, the following CD-DA track onthe CD may be sought and data may be read from that CD-DA track.

Moreover, in the seventh aspect, when a period during which the ejectionbutton is depressed is less than a predetermined time at the timingstep, a check may be performed to determine whether or not data arebeing read from a CD-DA track, and when data are being read, the datareading may be halted. On the contrary, when data reading is not beingperformed, the tray may be ejected by the command mechanism.

According to the present invention, when an ejection button is depressedduring the halting or the replaying, the CD-ROM drive performs theoperations that are shown in the Table of FIG. 9.

As is apparent from FIG. 9, a CD-ROM drive according to the presentinvention can employ a single ejection button to instruct all of theoperations, such as the start of the replaying for a music CD, thehalting of its replaying, the heal seek-and-set process for a succeedingmusical piece, and the ejection of the CD. "X seconds" in the Table ofFIG. 9 is determined by using a default value that is given in advanceor by the firmware setup within n the CD-ROM drive. The value of X maybe dynamically reset by using a jumper switch or by entering a systemcommand. In article D-2 of the embodiments below, x=2 [sec.].

An ejection button is one of the standard features of an incorporatedtype CD-ROM drive, as is shown in FIG. 1, and thus does not increase themanufacturing costs. Since the operations that are shown in FIG. 9 canbe performed by firmware within the CD-ROM drive, they have no effect atall on the design of a notebook computer system.

According to the present invention, when a user needs to take a break bylistening to music while working (e.g., preparing a document by wordprocessing), the user can realize such a desire simply by depressing anejection button.

The basic operations, such as the start of replaying for a music CD, thehalting of the replaying, and the head seek-and-set process for thesucceeding musical piece, can be performed without involving anycomputer system control functions. The computer system does not have toterminate the application that is being executed. Therefore, no specialeffort nor time need be expended by a user to play a music CD, and"working while listening to music" is a concept that can be easilyrealized, depending on the mood of the moment.

In addition, an application (CD-PLAYER.EXE) for the operation of a musicCD does not have to be loaded into the main memory of the computersystem. Further, it is not necessary for MSCDEX.EXE and a device driverfor a CD-ROM drive to be resident in the main memory simply for thereplaying of a music CD. Therefore, the present invention saves on thesystem resource requirements.

Other objects, features, and advantages of the present invention willbecome obvious from the detailed description of the following embodimentthat is given while referring to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an outline view of a notebook computer having a built-inCD-ROM player;

FIG. 2 is a schematic diagram of the hardware arrangement of a preferredembodiment of the present invention;

FIG. 3 is a schematic diagram of the hardware arrangement of a CD-ROMplayer used with the embodiment of FIG. 2;

FIG. 4a is a perspective plan view of a surface of a compact disk (CD);

FIG. 4b is schematic diagram showing the physical format of a CD such asthat shown in FIG. 4a;

FIG. 5a is a schematic diagram of the program area and the Table ofContents (TOC) arranged on a CD;

FIG. 5b is a schematic diagram of the field structure of one of thechannels arranged on a CD;

FIG. 6 is a flowchart of the operation when a disk in the CD-ROM driveis replaced;

FIG. 7 is a schematic diagram of the recorded contents of the RandomAccess Memory (RAM) after the processing of the flowchart of FIG. 6 iscompleted;

FIG. 8 is a flowchart of the operation when the ejection button of theCD-ROM drive is depressed;

FIG. 9 is a table of the operations performed when the ejection buttonis depressed;

FIG. 10 is a table showing the relationship between PSec Field valuesand compact disk types; and

FIG. 11 is a table showing the relationship between the Control fieldvalues and disk track types.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, the description of the embodiment of thepresent invention will be divided into the following articles forconvenience

A. Hardware arrangement of a computer

B. Hardware arrangement of a CD-ROM drive

C. Data structure of a compact disk

D. Operation of a CD-ROM drive

E. Appendix

A. Hardware Arrangement of a Computer

FIG. 2 is a schematic diagram illustrating the hardware arrangement of anotebook computer 1 that is employed to carry out the present invention.

In FIG. 2 a Central Processing Unit (CPU) 7 executes an applicationprogram under the control of an operating system (OS). The CPU 7communicates with the individual sections by means of a transfer path(bus) 8 for the transmission of address signals such as address signals,data signals, and control signals. The individual components will now beexplained.

A main memory 9 is a volatile memory, Random Access Memory (RAM), intowhich the individual programs are loaded and that serves as a work areafor the CPU 7. A Read Only Memory (ROM) 10 is a non-volatile memory inwhich a POST (Power On Self Test) program and a BIOS (Basic Input/OutputSystem) for hardware control are encoded and permanently stored.

A Direct Memory Access Controller (DMAC) 11 is a special processor bywhich data are transferred between the main memory 9 and peripheraldevices without passing through the CPU 7.

An interrupt controller 12 is a processor that monitors the bus 8 andreports to the CPU 7 any occurrence of interrupt on the bus 8. A videocontroller 13 is a processor that processes a video command from the CPU7. A VRAM 14 is a processor that temporarily stores video data that arebeing processed. An LCD 4 is a device that displays the contents of theVRAM 14.

An audio controller 15 is a processor that handles the input and theoutput of audio signals. An audio signal is amplified by an amplifier 16and the amplified signal is output through a loudspeaker 17. Theamplifier 16 receives an analog signal also from a CD-ROM drive 50 via asignal line 52 (which will be described later).

An HDD 18 and an FDD 20 are auxiliary storage devices. An FDC 19 is acontroller that drives the FDD 20.

In addition to the HDD 18 and the FDD 20, the notebook computer 1includes a CD-ROM drive 50 as an auxiliary storage device. The CD-ROMdrive 50 is connected via the bus 8 to a bus connector 51 for theexchange of commands and of digital data, and outputs analog datadirectly to the amplifier 16 via the signal line 52 (the details will beexplained in article B).

An I/O controller 24 is a controller that enables, data exchange with amodem or a printer (not shown) via a serial port 25 and a parallel port26.

The computer 1 includes a keyboard 22 and a mouse 23 with which a userinputs data and commands. An input matrix from the keyboard 22 andpointed coordinates from the mouse 23 are processed by a keyboard/mousecontroller (KMC) 21.

The components in the hardware arrangement of the computer 1 that aredescribed in this article are well known to one having ordinary skill inthe art. Besides these components in FIG. 2, there are various otherhardware components (controllers, interface circuits, peripheraldevices, etc.) that constitute a notebook computer. It would beunderstood for one having ordinary skill in the art that to simplify theexplanation some components are not shown in this specification.

B. Hardware Arrangement of a CD-ROM Drive FIG. 3 shows the hardwarearrangement of the incorporated CD-ROM drive 50 that is employed tocarry out the principles of the present invention. The individualcomponents of the CD-ROM drive 50 will be explained.

A compact disk (CD) 53, which is a recording medium, is rotatablymounted on a spindle motor 54. An optical head (Pick-Up-Head) 55 islocated under the lower surface of the disk 53. To read data, theoptical head 55, which transmits a laser beam to the disk 53 andreceives its reflected beam, is mounted on a slider motor 56 that can beshifted in a direction of the radius of the disk 53. A motor driver 57controls the or spindle motor 54 and the slider motor 56 so as to rotatethe tracks of the disk 53 at constant linear velocity (CLV) relative tothe optical head 55.

A signal that is outputted by the optical head 55 is transmitted to anRF amplifier 58 to control the position of the optical head 55 and toread data from the disk 53. For the position control, a closed loopcontrol system, which includes a servo circuit 59-1 and the motor driver57, synchronously drives the spindle motor 54 and the slider motor 56 inresponse to the output signal from the optical head 55. This permitsaccess by the optical head 55 to a predetermined position on the disk53. The optical head 55 is supported by a double-axis device (not shown)that can be shifted slightly, and thus focusing correction and trackingcorrection are permitted.

FIG. 3 shows the hardware arrangement of the incorporated CD-ROM drive50 that is employed to carry out the principles of the presentinvention. The individual components of the CD-ROM drive 50 will beexplained.

A compact disk (CD) 53, which is a recording medium, is rotatablymounted on a spindle motor 54. An optical head (Pick-Up-Head) 55 islocated under the lower surface of the disk 53. To read data, theoptical head 55, which transmits a laser beam to the disk 53 andreceives its reflected beam, is mounted on a slider motor 56 that can beshifted in a direction of the radius of the disk 53. A motor driver 57controls the or spindle motor 54 a:nd the slider motor 56 so as torotate the tracks of the disk 53 at constant linear velocity (CLV)relative to the optical head 55.

A signal that is outputted by the optical head 55 is transmitted to anRF amplifier 58 to control the position of the optical head 55 and toread data from the disk 53. For the position control, a closed loopcontrol system, which includes a servo circuit 59-1 and the motor driver57, synchronously drives the spindle motor 54 and the slider motor 56 inresponse to the output signal from the optical head 55. This permitsaccess by the optical head 55 to a predetermined position on the disk53. The optical head 55 is supported by a double-axis device (not shown)that can be shifted slightly, and thus focusing correction and trackingcorrection are permitted.

For the reading of data on the disk 53, a signal that is output from theoptical head 55 is processed by a digital signal processor (DSPI) 59-2and the resulting signal is converted into an analog signal by adigital-analog converter (DAC) 60. The analog signal is amplified by anaudio amplifier 61, and the amplified signal is outputted either througha headphone jack (not shown) of the CD-ROM drive 50, or from the lineout terminal to the amplifier 16 of the computer 1 via the signal line52. To output the read-out data as digital data, the data are decoded bya decoder 62-1 and the decoded data are then transmitted to the bus 8 ofthe computer I via the bus connector 51. In this embodiment, the servocircuit 59-1 and the digital signal processor 59-2 are constructed as asingle chip.

A tray (see FIG. 1), on which the disk 53 is placed so as to beexchangeable is coupled to a loading motor 63, so that the tray can beinserted and ejected. An ejection button 6 is a control button that isprovided on the front face of the CD-ROM drive 50 (see FIG. 1) tocontrol operations, such as the insertion/ejection of the tray. When theejection button 6 is depressed, it sends a signal via a signal line 64to a controller or command mechanism 66. The motor driver 65 thereafterdrives the loading motor 63 in response to a control signal receivedfrom the controller 66.

The controller 66 controls the individual sections in the CD-ROM drive50. More specifically, the controller or command mechanism 66 performs apredetermined process on a signal that is received from the ejectionbutton 6 via the signal line 64. It controls the operations of theCD-ROM drive 50, such as the reading of data from the surface of thedisk 53 and the halting of the reading. It controls the insertion andejection of the tray (the details will be described in article D-2). Inaddition, the controller 66 includes a clock 67 for counting operationaltiming, a ROM 68, and a RAM 69.

The ROM 68 is a read only memory for permanently storing data and isemployed for recording various firmware. The firmware includes, forexample, (A) code for a self-test that the drive 50 performs whenpowered on, (B) code for the interpretation of a command that isreceived from the computer 1 via the bus 8, (c) code for theconfirmation of the state of the drive 50, such as disk in/out or trayin/out, and (d) code for the mechanical control in the drive 50. Aprogram that accomplishes the operation that will be described inarticle D and a software timer that measures the period that theejection button 6 is depressed are included in the firmware in the ROM68.

The RAM 69 is a writable memory that is employed as a work area for thecontroller 66. In the RAM 69 is stored a variety of information about adisk that is currently loaded (e.g., file allocation information such asTOC (which will be described later)), a drive parameter that indicates adata transfer speed, and an audio parameter that indicates a soundoutput level.

An interface circuit 62-2, which permits the exchange of digital data bythe bus 8 of the computer 1 and the CD-ROM drive 50, is connected to thebus 8 via the bus connector 5:1. As for the standards for an interfacethat connects the CD-ROM 50 to the bus 8 of the personal computer 1,although in addition to the SCSI and Enhanced IDE standards there areothers that have been specified by individual makers, no limitations areimposed on interface standards for the realization of the presentinvention.

SCSI is an abbreviation of Small Computer System Interface, and thestandards for peripheral interfaces, for a compact computer, which arestandardized by the American National Standards Institute (ANSI). IDE isan abbreviation of Integrated Drive Electronics, and is one of theinterfaces that are used to directly connect a hard disk to an ISA bus.Enhanced IDE is an enhanced version for a CD-ROM drive.

In this embodiment, the decoder 62-1 and the interface circuit 62-2 areconstituted as a single chip.

The hardware arrangement of- the CD-ROM drive 50 explained in thisarticle (except for the firmware in the ROM 68 that is used for specificoperations that will be explained in article D) is well known to onehaving ordinary skill in the art. Although the CD-ROM drive 50 includeshardware components other than those shown in FIG. 3, those componentsare well known and to simplify the description no explanation are givenfor them in this specification.

It should be noted that when audio data in an arbitrarily CD-DA track onthe disk 53 are read and converted into an analog signal by the DAconverter 60, and the converted analog signal is output from the lineout terminal 52 to the amplifier 16 of the computer 1, or is amplifiedby the audio amplifier 61 and the amplified signal is output to aheadphone, the replaying of a music CD can be performed. While replayinga music CD,, the CD-ROM drive 50 does not require any exchange ofcommands and data via the bus connector 51, i.e., does not use the bus 8of the computer 1 at all.

C. Data Structure of a Compact Disk

An explanation has been given in "Background of the Invention" that dataare recorded spirally on the disk surface with the same density, andspiraling from the center, the data area is divided into a lead-in area,a program area, and a lead-out area (see FIG. 4). In this article, tosimplify the explanation in article D, the physical format of a CD willbe explained in more detail.

FIG. 4(b) is a schematic diagram showing a physical format of a CD. Onesession is so formed that a program area that is substantially user datais sandwiched between a lead-in area and a lead-out area. Although a CDnormally carries only one session (single-session), a "Photo CD" onwhich photograph images are recorded is a multi-loading type thatcarries a plurality of sessions (multi-session). Since the Photo CD doesnot include audio data (CD-DA tracks), it can not be used with thisembodiment of the present invention.

A maximum of 99 tracks can be stored in the program area. One CD-DAtrack corresponds to one piece of music and the number of tracks in adisk that is dedicated to music corresponds to the number of musicalpieces. One track can be further divided into frames. A frame is theminimum unit for data processing, and consists of 24 bytes. A group of98 sequential frames (2352 byte length) is called a sector. The lengthof a track is not constant. In the case of a CDDA track, the number ofsectors that is included in one track is determined according to theplaying period for a music piece.

Various control information, such as attribute information and startpositions of tracks, are recorded in the lead-in area and the lead-outarea. In the lead-in area is stored a table, a so-called TOC (Table OfContents), for managing attribute information and control information onthe disk by track units. As is shown in FIG. 5(a), in the TOC, onerecord that consists of 96 bits, a so-called "Q channel," is preparedfor each track, and the Q channels are stored in the order of the tracksin the program area. The data structure of a Q channel conforms to afield structure (called a "Q format") that is shown in FIG. 5(b), anddata for the tracks are stored in the corresponding fields.

Values that are stored in the individual fields (Control, ADR, in the Qchannel are employed during a track seek on the CD or when the data inthe track are read. Especially, the control field value and the PSecfield value are employed for the operation of the CD-ROM drive 50, whichwill be described in the succeeding article D, and will therefore be butbriefly explained below.

The PSec field is employed to represent a disk type. The Table of FIG.10 shows the relationship between PSec Field values and disk types.According to FIG. 10, when PSec=00h, the disk consists of CD-DA tracks(including CD-Graphics), CD-ROM tracks, or hybrid CD-DA tracks andCD-ROM tracks. In other words, when PSec=00h, the disk may include audiodata (CD-DA tracks). When PSec=10h, the disk is a CD-I type, and whenPSec =20h, the disk is a CD-ROM XA type. Therefore, with any value otherthan PSec=00h, the disk does not include audio data in a CD-DA format(i.e., in a format that is not interleaved).

Generally, tracks with different PSec values do not coexist on a singledisk. Whether or not a disk includes a CD-DA track can be determined byreferring to one PSec value of an arbitrary single Q channel in the TOC.

The control field is employed to represent a corresponding track type.The Table of FIG. 11 shows the relationship between the Control fieldvalues and track types. According to FIG. 11, when the second bit fromthe top is "0," its corresponding track is a CD-DA or CD-Graphics type.When that bit is "1," its corresponding track is a CD-ROM type. In thismanner, whether or not a corresponding track is a CD-DA type (audiodata) can be determined by referring to the second bit from the top inthe Control field in the Q channel.

The physical format for a CD that is shown in FIGS. 4 and 5 is a wellknown format that was determined by Sony Corporation and Philips Ltd.

D. Operation of a CD-ROM Drive

The hardware arrangement and the other arrangement that practices theprinciples of the present invention have been explained in articles Athrough C. In article D, the operation of the CD-ROM 50 that employsthese arrangements will be explained. The operation of the CD-ROM 50 canbe performed by the firmware in the ROM 68 (FIG. 3).

D-1. Operation when a Compact Disk is Exchanged

The operation when a compact disk in the CD-RON drive 50 is exchangedwill be explained in this article while referring to the flowchart inFIG. 6.

Following the insertion of the tray of the CD-ROM 50 at step S10, atstep S12, a check is performed to determine whether or not a disk existson the tray. The presence of the disk can be easily determined bydetecting the amount of light that the optical head 55 has received.

If the decision at step S12 is affirmative, at step S14, a Disk-in flagthat indicates the presence of a disk is set at predeterminedaddress#bbbb in the RAM 69, and program control advances to step S16. Ifthe decision at step S12 is negative, program control branches to No andreturns to the initial step.

At step S16, a check is performed to determine whether or not access ofthe loaded disk is possible. This check is required because sometimesdata can not be read out due to a dirty disk surface or a scratched disksurface. When the decision at step S16 is affirmative, at step S18, aValidity flag, indicating that access of the disk has been validated, isset at predetermined address #cccc in the RAM 69. Program control thenadvances to step S20. When the decision at step S16 is negative, thefurther process steps for accepting the disk is not performed and theprocessing is terminated in failure (ABORT).

At step S20, the TOC is read out by accessing the lead-in area, which islocated inward on the disk, and is stored at predetermined address #aaaaand its following address in the RAM 69.

FIG. 7 is a specific diagram showing the recorded contents in the RAM 69after the processing in tile flowchart in FIG. 6 is terminatedsuccessfully. The controller 66 does not use, as work areas, the areasin the RAM 69 where the TOC and these flags are stored. The stored TOCand flags are saved until the next replacement of the disk (or theejection of the tray).

The operation shown in FIG. 6 is a normal disk replacement operationthat is performed in almost all current CD-ROM drives, regardless ofwhether or not the present invention is employed. It should be notedthat to store the TOC of a loaded disk at a predetermined address in theRAM 69 and to set a Disc-in flag and a Validity flag (or data equivalentto these flags) are requirements for performing an operation in thesucceeding article D-2.

D-2. Operation when an Ejection Button is depressed The operationperformed when an ejection button of the CDROM drive 50 is depressedwill now be described while referring to the flowchart in FIG. 8.

When the ejection button 6 of the CD-ROM drive 50 is depressed at stepS30, a depression time T is counted at step S32. The counting of thetime T is performed by the software timer (previously described) of theROM 68. When T is two seconds or longer, program control branches to Yesand advances to step S34. When T is shorter than two seconds, programcontrol branches to No and moves to step S52. In this embodiment, aperiod of two seconds is predetermined by the firmware in the ROM 68,but may be dynamically altered by a jumper switch or a system command.

At step S34, a check is performed to determine whether or not a CD-DAtrack on a disk is being replayed.

When the decision at step S34 is negative, the depression for twoseconds or longer at step S30 is regarded as a request for the"replaying of a music CD." Program control then branches to No and movesto step S36, and a check is performed to determine whether or not anaccessible disk is positioned on the tray. The determination is made byexamining whether or not the Disk-in flag and the Validity flag havebeen set at the respective addresses#bbbb and #cccc in the RAM 69.

At step S38, a check is performed to determine whether or not there is apossibility that audio data (a CD-DA track) exists on the loaded disk.The determination is made by accessing the TOC, which is stored at apredetermined address following address #aaaa in the RAM 69, and byreferring to a value in the PSec field of an arbitrary Q channel. WhenPSec=00h, the decision at step S38 is affirmative. When PSec has anothervalue, the result at step S38 is negative.

When the result at one of steps S36 and S38 is negative, the depressionof the ejection button 6 at step S30 is regarded as a request for "trayejection." Program control thus advances to step S50 ([Eject]) where thetray is ejected. When the results at both steps S36 and S38 areaffirmative, at step S40, one of the Q channels is read from the head ofthe TOC that is stored in the RAM 69. Then, at step S42, by referring tothe second bit: from the top of the Control field value in the Qchannel, a check is performed to determine whether or not acorresponding track is a CD-DA track.

If the decision at step S42 is affirmative, program control advances tostep S44 ([PLAY]) where that track is played (i.e., the music CD isplayed). When the playing of the track has been completed, programcontrol advances to step S46, where a seek is performed for the nexttrack. If the decision at step S42 is negative (that is, the track isnot a CD-DA track), the track playing at step S44 is skipped and a seekis performed for the next track at step S46. When, at step S48, the nexttrack is found as the result of the seek procedure at step S46, programcontrol branches to Yes and returns to step S40. The same process isrepeated. By the performance of such loop processing, CD-DA tracks onthe disk are sequentially found and music is played. When, at step S48,no next track is found, all the CD-DA tracks on the disk have beenplayed. Program control thus branches to No and moves to step S54([STOP]).

When, at step S34, the playing of a CD-DA track on the disk has begun,the depression of the ejection button 6 for two seconds or longer thatwas performed at step S30 is regarded as a request for a "headseek-and-set process for the next musical piece." Program control thenbranches to Yes and goes to step S46, where a seek is performed for thenext track and the same process as is described above is performed.

If, at step S32, the depression time for the ejection button 6 is lessthan two seconds, program control branches to No and goes to step S52.At step S52, a check is performed to determine whether or not the CD-DAtrack on the disk is being played. When playing has begun, thedepression of the ejection button 6 is regarded as a request for"halting the playing of a music CD." Program control branches to Yes andgoes to step S54 ([STOP]). When the playing of the CD-DA track is notbeing performed, the depression of the ejection button 6 is regarded asa request for a "tray ejection." Program control branches to No andmoves to step S50 ([EJECT]).

It would be easily inferred that steps S44, S50, and S54, which areenclosed by double lines in FIG. 8, correspond respectively to (PLAY(play start)], [EJECT], and (STOP (play halt)] buttons.

In short, through the processing in the flowchart: in FIG. 8, thecontroller or command mechanism 66 monitors the depression of theejection button 6, and the combination of the manipulation of theejection button 6 and the operational state of the CD-ROM drive 50accomplishes the individual operations relative to a music CD. It shouldbe fully understood that this processing is the core of the concept ofthe present invention. It should also be fully understood that terms"play" and "replay" in this specification indicate that audio data in aCD-DA track on the loaded disk are read, converted into analog data bythe DA converter 60, and outputted without any change. Further, itshould be noted that the bus connector 51 (i.e., the bus 8 of thecomputer 1) is not used for the operation of a music CD.

In this embodiment, only a CD-DA track is employed for replaying.However, it would be obvious that, so long as audio data that areinterleaved and recorded can be decoded inside the CD-ROM drive, theconcept of the present invention can be applied for a track conformingto CD-I format or CD-ROM XA format.

The present invention has been described in detail while referring tothe specific illustrated embodiment. However, it should be obvious forone having ordinary skill in the art that various modifications orrevisions of the embodiment are possible within the scope of the presentinvention. For example, while a notebook computer is employed for theexplanation of the embodiment of the present invention, a CD replaydevice according to the present invention can also be employed withother types of portable information processing apparatus (such as wordprocessors or other OA devices). That is, although the present inventionhas been disclosed by using an example, it should not be limited to thatexample. To understand the subject of the present invention, thefollowing claims should be referred to.

As described above in detail, according to the present invention, it ispossible to provide a CD replay device that can be incorporated in anotebook computer and that can easily replay a music CD withoutinterrupting an application, which is being executed by a computersystem, and to a method for controlling such a CD replay device.

An ejection button itself is one of the standard features for anincorporated CD-ROM drive, as is shown in FIG. 1, and thus does notincrease the manufacturing costs. Since the operations as shown in FIG.9 can be performed inside the CD-ROM drive by firmware, the design of anotebook computer system is not affected at all.

The basic operations, such as the beginning of the replaying of a musicCD, the halting of the replaying, and the head seek-and-set process forthe next piece of music, can be performed without requiring the controlof a computer system, and the computer system does not have to terminatethe application that is being executed. Therefore, when a user desiresto relax by listening to music, the gratification of the desire can beobtained simply by depressing the ejection button, so that "workingwhile listening to music" is a concept that can be easily realized,depending on the mood of the moment.

Further, since it is not necessary for an application for operating amusic CD and a device driver for a CD-ROM drive to be resident in themain memory of a computer system, system resources can be saved.

What is claimed is:
 1. A personal computer having a CPU, an integratedCD player and a CD replay device with the CD player device being adaptedto read data from a surface of a CD disk mounted in the CD player andbeing ejectable therefrom without interrupting an application programbeing executed by the computer and wherein the CD replay devicecomprises:a single control means for controlling the reading of datafrom said CD and for controlling the ejection of said CD from saidreplay device when said control means is operated; and means for timingthe period during which said control means is operated whereby said CDis ejected from said replay device when said control means is operatedfor a time period less than a predetermined time period and said replaydevice reads data from the surface of said CD when said control means isoperated for a time period equal to or longer than said predeterminedtime period.
 2. A computer having a CD replay device as claimed in claim1, wherein said surface of said CD disk has a plurality of tracksthereon and the reading of data from said surface of said CD disk ishalted when said control means has been operated for a time period lessthan said predetermined time period during the reading of a track onsaid surface and the reading of said surface begins on a different trackwhen said control means has been operated for a time period equal to orlonger than said predetermined time period.
 3. A device as claimed inclaim 2, wherein said control means is an ejection button and isoperated when said button is depressed.
 4. A device as claimed in claim3, wherein said control means is an ejection button and is operated whensaid button is depressed.
 5. A method for operating a personal computerhaving a CD player and a CD replay device integrated therein such thatthe CD replay device reads data from a CD mounted in the CD playerwithout interrupting an application program being executed by thecomputer, said CD replay device including a single control member forcontrolling the ejection of said CD, with said CD having a plurality oftracks, said method comprising the steps of:halting the replaying ofsaid CD when said control member has been depressed for a period of timethat is less than a predetermined time during the replaying of said CD;and beginning the replaying of the next track on said CD when saidcontrol member has been depressed for said predetermined time during thereplaying of said CD.
 6. A method as claimed in claim 5, wherein saidcontrol member is an ejection button which is operated by depressing thebutton.
 7. A method for operating a personal computer having a CPU, acomputer system with a main memory, a CD player and a CD replay deviceintegrated into said personal computer through a common bus such thatthe CD replay device reads data from a CD mounted in the CD playerwithout interrupting an application program being executed by thecomputer with said CD replay device comprising:a tray on which a CDplayer is placed, a discharge mechanism for inserting and ejecting saidCD from said tray, an ejection button to control the ejection of saidtray, a read mechanism for seeking data on a surface of said CD and forreading said data, a data processor for processing data, a line outterminal for relaying an analog output of said data, an interface forconnecting said CD replay device to said bus and a controller forcontrolling all the operations, said methods comprising the stepsof:initiating the operation of said discharge mechanism for dischargingsaid CD when said ejection button is depressed for a period that isshorter than a predetermined time while said read mechanism is halted;beginning data reading by said read mechanism when said ejection buttonis depressed for said predetermined time; and outputting the data readfrom said line out terminal.
 8. A method as defined in claim 6 furthercomprising:skipping the track position on said CD to a succeeding trackwhen said ejection button is depressed for said predetermined timeperiod and said data is being read by said read mechanism.
 9. A methodfor operating a personal computer having a CPU, a computer system with amain memory, a CD player and CD replay device integrated in saidpersonal computer through a common bus such that the CD replay devicereads data from a CD mounted in the CD player without interrupting anapplication program being executed by the computer, said CD replaydevice comprising a tray on which a CD having a plurality of tracks isplaced, a discharge mechanism for inserting and ejecting said tray, anejection button to control the ejection of said tray, a read mechanismfor seeking data on a surface of said CD and for reading said data, adata processor for processing data, a line out terminal for relaying ananalog output of said data that are read, an interface for connectingsaid CD replay device to said bus, and a controller for controlling allthe operations, wherein data is read from a CD-DA track and an analogoutput of said data can be transmitted from said line out of terminal,said method comprising the steps of:a timing step of timing a periodduring which said ejection button is depressed; a first decision step ofdetermining whether or not a CD-DA track is being read when, at saidtiming step, said period is of a predetermined period; a second decisionstep of determining whether or not a CD has been placed on said traywhen, at said first decision step, no reading of CD-DA track is beingperformed; a third decision step of determining whether or not a CD-DAtrack is included on said CD when, at said second decision step, said CDis determined to be placed on said tray; a seeking step of seeking thenext CD-DA track when, at said third decision step, it is determinedthat CD-DA track is included on said CD; and a playing step of read datafrom the CD-DA track that is found at said seeking step and of providingat said line out terminal an analog output of said data that is read.10. A method for controlling a CD replay device according to claim 9,wherein when the data reading from the CD-DA track has been completed atsaid playing step, a following CD-DA track is sought on said CD and saidplaying step is repeated.
 11. A method for controlling a CD replaydevice according to claim 10, wherein, when the result obtained by oneof said second and said third decision steps is negative, said tray isejected by said discharge mechanism.
 12. A method for controlling a CDreplay device according to claim 9, wherein when data are being readfrom said CD-DA track at said first decision step, a following CD-DAtrack on said CD is sought and data may be read from said CD-DA track.13. A method for controlling a CD replay device according to claim 9,wherein, when a period during which said ejection button is depressed isless than a predetermined time at said timing step, a check is performedto determine whether or not data are being read from a CD-DA track, andwhen data are being read, said data reading is halted.
 14. A method forcontrolling a CD replay device according to claim 9, wherein, when aperiod during which said ejection button is depressed is less then apredetermined time at said timing step, a check is performed todetermine whether or not data are being read from a CD-DA track, andwhen data reading is not being performed, said tray is ejected by saiddischarge mechanism.